The polymerization of a monoepoxy, phenylglycidylether (PGE), initiated by BF3-4-methoxyaniline (BF3-4MA) was studied at 60-degrees-C. The polymerization rate was found to be R(p) = k(p) [BF3-4MA ]0.53 [PGE]. The improper fraction of BF3-4MA shows the complexity of the polymerization mechanism. Moreover, the influence of water, temperature, by-products formed during the polymerization, on the kinetics of PGE was also examined. Furthermore, two other monoepoxy monomers, glycidylmethacrylate (GMA) and alpha-napthylglycidylether (NGE), were studied for the comparison with PGE. Finally, an overall mechanism of the cationic polymerization of epoxy by BF3-amine complex was proposed.